Friday, April 29, 2011

In the windows phone 7 course I recently followed, there was an issue in unit testing a windows phone 7 project (you can find my recent post on this course here). The fact is, you can't create a Visual Studio unit test project for your phone project. Does this mean you cannot unit test your project? Of course it doesn't! Here's a solution to this problem.

First of all, I am using the MVVM pattern in my windows phone 7 project. This means my views, viewmodels and models are separated from each other, so I can place them in different projects. I created a normal windows phone 7 project for my views and a different windows phone 7 class library project for my viewmodels and models. Next thing you can now do is create a third project, also of the windows phone class library kind, which will contain your unit tests. You can see this basic setup in the following picture.

The fact that you take a windows phone 7 class library project for your unit tests is important. This solution will not work if you choose to use for instance a Silverlight class library project.
To this test project I now added the NUnit and Rhinomock dll's using Nuget and with this I can test all I want. One thing I still encountered was an error in my Unit Tests telling me the System.Windows dll could not be found.

This is quite a weird error, especially since the System.Windows.dll is present as reference in the test project. I tried adding different versions of this dll (all in my C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\Silverlight\v4.0\Profile\WindowsPhone folder), but no luck. Eventually I found that the dll was present in the project, but it just didn't get copied to the bin/Debug folder. Changing its Copy Local setting to True did the trick (and I kicked myself for losing quite some time on this stupid error).
So, there you go, a quick and easy way to unit test windows phone 7 projects. Soon I hope to give you some posts about my first Silverlight game and after that my first XNA game.

Thursday, April 28, 2011

This is already the fourth part in this series (for the full story, see posts 1, 2 and 3). And as promised, I'm going to do something a bit more advanced in this post. I will introduce you to the ExpandoObject and, in a fifth post, the DynamicObject classes. They bring you new opportunities for dynamically expanding your code, hence the term EXPANDOObject. Something you can, for instance also do in dynamic languages like Ruby (in one of the next posts I will show you some IronRuby code).

The ExpandoObject can be found in de System.Dynamic namespace (system.core.dll) and is actually a kind of key value set of keys (names) and implementations for these keys. These implementations can be fields, methods, properties, delegates, ... The funky thing is, you can add these implementations at runtime. You can start of with an ExpandoObject with no functionality at all and you can add functionality as you go. The following line of code gives you an empty ExpandoObject:

Besides this dynamically adding of functionality, the ExpandoObject is actually nothing more than a fancy key value set. It actually implements the IDictionary interface, which means you can enumerate all members you have just added.

Now, this is where most examples on ExpandoObject stop. It explains the use of the class, and that's it. On the other hand, this is where I start thinking, ok, cool, but what's the use? I mean, how can I use this dynamic run time behaviour in my everyday coding life. For this, in my opinion, the ExpandoObject runs a little short. The fact that an ExpandoObject is actually nothing more than a fancy dictionary means you can also add functionality through this dictionary, but this is a little pain staking, so I will not go into this. You will, however, get more practical use out of the DynamicObject class, which I will explain in the next post on this subject.

Tuesday, April 19, 2011

A couple of weeks ago I followed a two day Windows Phone 7 course (a little thank you to Microsoft for making this course free for Microsoft Partners is in place here). During the course, there were some small issues mentioned you need to take into account when developing for a Windows Phone 7 device that don't seem so obvious. Just to get you started, here's an overview of the most important stuff that's different from regular Silverlight development. I won't go into the gory details, just give you an overview of some stuff that I thought was a bit peculiar or different to what I was used to and some stuff you just need to know, which you don't find easily on the MSDN site.

First of all, when doing Windows Phone 7 development, you can use an emulator to see the result of all your hard coding work. That is, if you don't have the real stuff (which I don't, all donations are welcome!). When working with the emulator, one of the time consuming tasks, is typing in characters (eg. when editing a text box). The emulator gives you an on screen keyboard you can use to type, but this is not very practical when using your mouse! And if you try using your pc's keyboard to type, you'll find your key presses are not accepted.

There is, however a very quick and easy solution to use your pc's keyboard: just press your pause button (you know, the one you hardly ever use) and start to type. Once you're done typing, just press pause again. This will save you loads of time in the emulator.

Next, if you want to use animations in your Silverlight application, there are several ways to start a storyboard. You can do this with an event trigger in your XAML, using code, or by using the visual state manager. When developing for a Windows Phone 7 however, be aware that when using event triggers in XAML, only the Loaded event is available. Because you have this restriction, the better option to start a storyboard animation is by using code, just because it gives you more options.

Another difference is the absence of the NotifyOnException and NotifyOnValidation options you normally have for Silverlight databindings. These are just not there. If you get an error on your databinding, keep in mind, you will not see this in your interface.

If you want to unit test your Windows Phone 7 application you're out of luck. The standard unit test project type of Visual Studio is not compatible with the Windows Phone 7 project type. I am pretty sure however it must be possible to unit test your app using a 'plain old' NUnit class library (which I still think is a better option than the build in unit testing Visual Studio gives you).

One last, very small tip: don't close your emulator each time you change something in your code. It just increases the start-up time when you run your app. It's not a big thing, but it can truly save you a lot of time.

So, there you have it, some small, but still important things to keep in mind when developing for a Windows Phone 7 device. One of my next private projects will be a small 2D and 3D XNA app for the Windows Phone 7 (after teaching OpenGL and XNA a couple of years, I'm just aching to try this). I promise I will make some posts about it. And at this moment at QFrame (my company) we are also working on an (almost finished) Silverlight app for the phone, which uses Azure services and which we will demo at the Belgian TechDays 2011 next week. Be there!

Monday, April 4, 2011

In the first part of this series I gave an introduction to what the dynamic keyword can do for you. The second part of this series showed you how this dynamic keyword can be pretty handy when interoperating with javaScript code. in this third part we will look into interoperating with Excel. This part will be brief, though, mainly because there are already quite a lot of examples to be found concerning this subject.
In this post I will extend the example I started in the previous post. There, we've seen I get a list of Person data from a WCF service. This Person list is shown in a DataGrid control of a Silverlight application. The latest version of Silverlight, supports running out of browser and once you run out of browser you get some extra possibilities for your application. One of these possibilities is interacting with automation objects, like Excel. So, let's extend our example so it can run out of browser and also, so it can generate an Excel document.
Running out of browser is actually not that hard to do. The user of your application can right click on the Silverlight application and choose 'Install NameOfYourApplication onto this computer'.

To offer this right click functionality to your users you need to check the 'Enable running application out of the browser' checkbox in the project settings of your Silverlight application.

The button control under this checkbox will show a popup window with some extra settings. One of these extra settings, 'require elevated trust', is important if you want to offer automation functionalities in your out of browser Silverlight application, so you should check this as well.

Once you have done this, your users can install your application.

In code it is possible to test whether or not you are running out of browser. I, for instance, added some code to disable a button that generates HTML if we are running out of browser, since generating HTML is pretty useless if you're not running in a browser window (and if you do execute the generation of HTML out of browser you will get a runtime error, so better disable it).

btnHTML.IsEnabled = !Application.Current.IsRunningOutOfBrowser;

We can also test whether or not we can use the automation capabilities.

if (AutomationFactory.IsAvailable)

Once we know we have automation available, we can create a new Excel object. The return type of the GetObject and CreateObject calls is dynamic, so this is a good choice for the type of your variable.

The reason I use both GetObject and CreateObject is that if Excel is already running, we can get a reference to the application with GetObject. If Excel is not already running, we need to start, or create the application with CreateObject.

Once we have the Excel application at our disposal, we can create workbooks, we can add data to cells, etc. The good news is that, since version 4.0 of the .NET framework all objects in Excel (and in the other Office automation frameworks) are of type dynamic. This simply means you can omit a lot of casting operators. Where previously you needed to write code like this:

As you can see, there is a lot of casting going on in the first example, primarily to the Worksheet type and to the Range type. This is something we can completely omit when using dynamic. Which, in my opinion is a good thing!

The bad news, however, is, that with these dynamic types, your intellisense is gone. You need to know which operation calls are valid on which objects. But than again, who cares, because previously you needed to know which type you needed to cast to. If you got that one wrong, you'd get a runtime exception as well.

If you want to know even more on automation, this article in the MSDN library can give you some extra info.

That's it for the Office automation part of this series. Be ready to do some serious stuff with ExpandoObjects in the next post.

Sunday, April 3, 2011

After the basic intro given in the first part of this series, it is time for something more advanced. It won’t be rocket science, yet, but you will get more insight into what dynamic coding can do for you.As mentioned in the previous post, dynamic programming can help you a lot when working with COM objects. I will give an example of this for JavaScript objects in a small Silverlight application. In the next post I will extend this simple example and I will explain interaction with Excel. But first, let’s talk about JavaScript.Interacting with JavaScript might be something you need in real life. For instance if you have a Silverlight app that is hosted on a page that relies on JQuery a lot. JQuery can provide you with objects your SilverLight application does not know about. How can you interact with these objects if your managed code doesn’t know their type? The answer is to utilize dynamic.To illustrate this, suppose we have a service running that can give us data about persons. A Person being just a DTO class with a FirstName and LastName property. Plain and simple.

To illustrate how to work with such a JavaScript object, I’ve made a small Silverlight application that receives a list of person objects from the WCF service described above. The Silverlight application will display this list of persons in a DataGrid control.

This is the basic set up I will use in this example. The Silverlight application will be hosted on an HTML page that has the above mentioned JavaScript code present. In this example, to keep it simple, I will build a HTML table. It will be the Silverlight code that builds this table, not the JavaScript code. For this, first thing will be to get hold of a specific div tag on the HTML page in which we will build our table. Silverlight lets you interact with the hosting page through the HtmlPage class. This class gives you a Document property that behaves pretty much the same as the document object in JavaScript, which makes it very easy to use.

For each of these Person objects we will execute the GetSuperPerson function, present in the JavaScript of the hosting page. Since the Silverlight application has no knowledge of the SuperPerson type, we will use the capabilities of .NET 4.0.

With the dynamic keyword in place our compiler does not complain about the SuperPerson type it does not know about. And since we know a SuperPerson has a firstname, lastname and somethingextra, we can interact with it though these operations with no problem.

Two things are notable about the code above. First of all, I use firstname and lastname, not FirstName and LastName (mind the casing). This is because we are interacting with the JavaScript object, not with the original Person object. I purposely used other casing in the JavaScript code to make my point on this clear.A second thing you may have noticed is a second use of the dynamic keyword. When I create a new td element, I do not use the HtmlElement type (which is valid for a td tag), but instead I use the dynamic keyword. I do this because I know for sure it is possible to call the innerHtml operation on a td tag. The HtmlElement, however, does not have this operation present (you can check this in your intellisense). There is also no specific type for a td element that does have this operation present. With dynamic there is no problem at all to call innerHtml, not at compile time and not at run time.There you have it, two good reasons to use dynamic when you're interacting with JavaScript. You can get around unknown objects in managed code and you can call operations managed code has no clue of.Be ready for the next two parts, first on dynamic and Excel and next about ExpandoObjects (this is where the fun begins!).